Cautery

ABSTRACT

A hot wire surgical cautery has a casing which serves as a handle. A resistance wire cautery tip is connected to one end of the handle. Associated with the handle are two switches. The first switch responds to pressure from the surgeons&#39;&#39;s finger to cause electric current to flow through the tip and heat the tip to the desired cauterizing temperature. The other switch, which may be either a finger-pressure actuated switch similar to the first switch or a mercury switch automatically operated by raising the tip end of the tool, enables an electric circuit connected to the cautery to increase the voltage applied to the tip and thereby appreciably increasing the temperature thereof. This increase in temperature cleans the tip by burning off undesired residue clinging thereto. The increase in tip temperature for cleaning purposes is only temporary and the normal tip energization is automatically restored after a short period of time regardless of whether the second switch remains closed. A temperature control provides the exact tip temperature desired.

United States Patent Haffey [451 May 9,1972

[ CAUTERY Paul C. I-Iaffey, Duxbury, Mass.

[73] Assignee: Codman & Shurtleff, Inc.

[22] Filed: Nov. 17, 1969 [21] App]. No.: 877,339

[72] Inventor:

[52] U.S.Cl ..2l9/233,30/140,83/171, 128/303.14, 219/240, 219/501 [51] Int. Cl ..I-I05b l/00, H05b 1102 [58] Field oiSearch ..219/22l,227, 230, 231,233, 219/235, 241, 501, 232; 128/303.1-303.19; 30/140; 83/16, 171

[56] References Cited UNITED STATES PATENTS- 1,909,774 5/1933 Lindsay ..2l9/240 2,310,844 2/1943 Draeger... ...219/240 2,715,670 8/1955 Dicke ...219/235 2,814,712 11/1957 Fulmer 219/235 2,969,449 1/1961 Tyler 219/241 X 3,245,294 4/1966 Butter et al.. ..83/l6 3,247,358 4/1966 Schmidt ..219/240 F s: p

OTHER PUBLICATIONS GE Transistor Manual, Seventh Edition; General Electric Company, Semiconductor Products Dept, Electronics Park Syracuse, New York; published 1964. Pages 323 and 324 relied on.

Primary Examiner-A. Bartis AttorneyJames R. I-Iulen and Robert L. Minier [57] ABSTRACT A hot wire surgical cautery has a casing which serves as a handle. A resistance wire cautery tip is connected to one end of the handle. Associated with the handle are two switches. The first switch responds to pressure from the surgeonss finger to cause electric current to flow through the tip and heat the tip to the desired cauterizing temperature. The other switch, which may be either a finger-pressure actuated switch similar to the first switch or a mercury switch automatically operated by raising the tip end of the tool, enables an electric circuit connected to the cau'tery to increase the voltage applied to the tip and thereby appreciably increasing the temperature thereof. This increase in temperature cleans the tip by burning off undesired residue clinging thereto. The increase in tip temperature for cleaning purposes is only temporary and the normal tip energization is automatically restored after a short period of time regardless of whether the second switch remains closed. A temperature control provides the exact tip temperature desired.

9 Claims, 3 Drawing Figures S2 OR 82' CAUTERY This invention is an improved electrically operated surgical cautery.

In the use of anelectric cautery, the hot wire tip loop often requires cleaning to remove flesh tending to cling to the tip. If the tip is brushed against the surgeons clothes to remove the seared clinging debris, the tip may break and require replacement. This method of cleaning the tip consumes valuable time and often irritates the surgeon.

The cautery of the present invention eliminates the foregoing disadvantages and enables the fast, automatic cleaningof the cautery tip bya simple manipulation of the cautery handle.

According to one embodiment of the invention, a mercury switch within the handle enables the electric circuit connected to the cautery to increase the temperature of the hot wire tip quickly and automatically, merely by raising the tip end of the cautery above the horizontal position, to thereby burn off the debris clinging to tip.

According to another embodiment of the invention, the mercury switch is replaced by a pressure actuated switch in the handle.

A feature of the electric circuit connected to the cautery is that the increase in temperature of the tip for cleaning purposes is only temporary, and the normal operating flow of cur rent to the tip is restored automatically and in a very short period of time, regardless of whether the tip of the cautery continues to be raised or the pressure-actuated switch continues to be actuated.

Another feature of the electric circuit is that the normal operating temperature of the tip is controllable by a slider or potentiometer the position of which determines within a desired range the current flowing through and the heat generated by the wire tip.

A detailed description of the invention follows in conjunction with a drawing, wherein:

FIG. 1 illustrates the combination of the cautery of the invention in association with electrical circuitry. The cautery is shown only diagrammatically in FIG. 1 in generally box form;

FIG. 2 illustrates an embodiment of the cautery of the invention which incorporates a mercury switch within the handle casing of the cautery for enabling an increase in tip temperature; and

FIG. 3 illustrates another embodiment of the cautery of the invention wherein the mercury switch of FIG. 2 is replaced by a pressure-actuated switch.

Throughout the figures of the drawing, like parts are designated by like reference characters, while parts which are designated with prime markings are equivalent in function to their unprimed reference counterparts.

The cautery of the invention includes a handle or casing 10 having at one end a plug-in cautery tip assembly 12. The bandle 10 is a tubular housing made of plastic or other suitable insulating material containing within it a pressure-actuated switch $2. One end (the right hand end) of the handle may be fitted with a reduced tapering cap 14 having an end hole for accommodating the electrical conductors, in two-conductor jack form or otherwise, as disclosed and illustrated in U.S. Pat. No. 3,461,874 granted Aug. 19, 1969, for connection to the terminals of the wire loop tip assembly 12. No claim is being made to the design of the replaceable tip assembly which may take any suitable known form. The other end of the handle 10 is provided with a removable plastic cup 16. The closed end of cup 16 is provided with a hole through which passes a fourconductor cable 18 containing insulated wires 1, 2, 3 and 4. Insulated wires 3 and 4 are connected to the electrodes and 6, respectively, of a gravity operated switch S3 such as a mercury switch in the cautery of FIG. 2, while these same wires are connected to the terminals 5 and 6', respectively, of pressure-actuated switch S3 in FIG. 3. Insulated wires 1 and 2 are connected to the terminals of switches S2 and S2 of the cauteries shown respectively in FIGS. 2 and 3. I

The switch S2 of FIG. 2 includes a button 20 which rests upon a resilient contact spring 22 within the interior of handle 10. One end of spring 22 is supported by abracket 24 while the other end of spring 22 is adapted to engage a wire 26 connected to one terminal of the wire tip assembly in response to finger pressure on button 20. Mercury switch S3 is oriented so as to be on when the handle 10 is placed in a rest position with the wire tip end of handle 10 raised above the horizontal at a desired angle. In this position, the mercury M within the switch moves to bridge electrodes 5 and 6 of the switch. When the handle 10 is horizontal or the wire tip end downwardly inclined, as in the surgical operating position, the mercury switch S3 of the cautery of FIG. 2 is off." In this off position (as shown in FIG. 2), the mercury has moved away from the switch electrodes. The electrodes of the switch are no longer directly connected to each other by the mercury.

The four wires 1 to 4 inclusive of the cable 18 may terminate in a plug whose four pins may appropriately engage the four appropriately positioned registering receptacles of a socket, as shown in FIG. 1, The four connections of the socket are connected to the electrical circuitry for energizing the cautery.

The electrical circuitry of FIG. 1 comprises a plug P which is adapted to be inserted into the socket connected to the electrical power mainsfurnishing alternating current, for example, -115 volts AC. This current flows through a fuse F and a switch S1. When switch S1 is closed, alternating current flows through the primary winding of the step-up transformer T to provide alternating current across the secondary winding terminals AC. A variable resistor R in the form of a potentiometer or a slider arrangement has one end connected to an intermediate tap B on the secondary winding and its other end connected, via normally closed contacts NC of a relay, to wire 1 of the cautery as shown. An electronic device in the form of an NPN-transistor 28 having a suitable time constant circuit has its collector connected to secondary winding terminal A and wire 2 of the cautery, its emitter connected to the energizing winding W of a relay, and its base connected through a varia ble condenser C2 to wire 3 of the'cautery. The NPN-transistor 28 is arranged to be non-conducting (off) when only switch S2 of FIG. 2 or switch S2 of FIG. 3 is closed. This is the situation when the surgeon is using the cautery on a patient. In this condition, there is no current flowing through the operating winding W of a relay having normally closed contacts N.C. and normally open contacts N.O. When the mercury switch S3 of FIG. 2 is closed, as by elevating the wire tip end of the handle, or pressure-actuated switch S3 of FIG. 3 is closed, the transistor 28 is turned on (becomes conducting) to enable current to flow therethrough and energize the operating winding W of the relay. The energization of relay winding W will open nonnally closed contacts N.C. and close the normally open contacts ND. The result of operating relay W is to supply an increased flow of alternating current to the wire loop tip via conductors l and 2, thereby greatly increasing the temperature of the wire tip to an extent sufficient to burn off any residue adhering to the tip, and achieve a cleaning action.

The manner in which the cautery of the invention and its associated circuitry operate will now be given:

During the normal searing or cutting operation of the patient by the surgeon using the cautery, the cautery will be downwardly inclined and the surgeon will close switch S2 by finger pressure. The transistor 28 is off. The wire tip 12 is energized by the flow of current appearing across the terminals A and B constituting the ends of the upper portion of the secondary winding of transformer T. The amount of current flow through the tip 12 and the temperature of the tip is a function of the position of the slider of potentiometer R. Varying the position of the slider on R will vary the amount of current through and, therefore, the heat generated by the heated wire tip 12. The current path for the wire tip in this condition includes the terminal A, conductor 2, the closed contacts of switch $2, the wire loop tip 12, conductor 1, normally closed contacts N.C., the variable resistor R and terminal tap B. Only a relatively small voltage appears across terminals A, B of a value sufficient to heat the wire tip 12 of the cautery to a desired temperature, for example, l,000 F.

When the surgeon desires to clean the wire tip 12, the handle of the cautery of FIG. 2 is raised to the rest position so that the end of the handle constituting the tip is elevated above the horizontal position in order to close mercury switch S3, while still maintaining switch S2 in the closed position. If the cautery embodiment of FIG. 3 is used, the mechanical switch S3 is pressure-actuated to close, also while maintaining switch S2 in the closed position. When switch S3 or S3 is closed, a forward bias is applied to the base of the NPN-transistor 28 to cause it to conduct and energize relay winding W, thereby operating the relay to open normally closed contacts NC. and to close normally open contacts N.O. In this condition, the voltage across the terminals A,C of the entire secondary winding is applied to the wire loop tip 12 over a path including terminal A, conductor 2, switch S2 or S2 depending upon which embodiment, FIG. 2 or FIG. 3, is used, the wire tip 12, normally open but now closed relay contacts N.O., resistor R1, and terminal C. The voltage across tip 12 is now limited only by the small resistor R1, thereby causing an increased current flow through and a higher temperature of the tip 12. By way of example, this increased temperature may be of the order of 1300 F. for cleaning or burning off seared flesh or residue adhering to the tip 12. The increase in temperature of the tip is only temporary and will automatically decrease down to the operating or cutting temperature due to the operation of the electrical circuitry, as will be described hereinafter. Transistor 28 is non-conductive prior to the closing of switch S3 or S3and capacitor C2 is uncharged. One switch S3 or $3 is closed, a positive voltage is applied to the base of transistor 28 to render the transistor conductive and energize relay winding W to increase the temperature at tip 12 to the cleaning temperature by closing contacts N.O. and opening contacts N.C., as described above.

Capacitor Cl and diode D1 effectively provide a positive DC source for the electric circuit; and, after transistor 28 has been rendered conductive, capacitor C2 charges until the base of transistor 28 is negative with respect to the emitter to render the transistor non-conductive. Thus, relay winding W is deenergized to open contacts N.O. and close contacts NC. to decrease the temperature of tip 12 to the cauterizing temperature a predetermined period of time after switch S3 or S3 is closed (for example, 2 seconds). Capacitor C2 remains charged to maintain transistor 28 non-conductive as long as switch S3 or $3 remains closed such that once switch S3 or S3 is closed the tip 12 will be raised to the cleaning temperature for only the predetermined period of time, which is dependent upon the time required to charge capacitor C2 sufficiently to render transistor 28 non-conductive, regardless of how long switch S3 or S3 remains uninterruptedly closed.

Once switch S3 or S3 is opened, capacitor C2 discharges through resistor R2 and diode D2 while transistor 28 remains non-conductive; and, as previously described, transistor 28 will be non-conductive when switch S3 or S3 is open to maintain the relay deenergized and tip 12 at the cauterizing temperature.

It will be appreciated that the electrical circuitry performs as a typical monostable multivibrator which produces a given time delay upon the receipt of a triggering input voltage pulse and will not again trigger to produce a time delay until another similar transition occurs. The relay including winding W and contacts N.O. and N.C. is operative to control electricity supplied to wire tip 12 in that when the relay is in a first deenergized state the wire tip is at the cauterizing temperature and when the relay is in a second energized state the wire tip is at the cleaning temperature; however, it will be appreciated that, while the disclosed control and timing circuitry is particularly advantageous due to its simplified structure, reduced number of components, precision and reliability, various circuits may be utilized to provide the required control and timing. The invention is, therefore, not limited to the particular electrical circuitry herein disclosed and described.

In one particular embodiment of the invention successfully tried out in practice, in both animals and humans, the components used in the electrical circuit, given by way of example only and not by way of limitation, had the following values:

Transformer T 6.3V, CT. 3A Triad Transistor 28 NPN The surgical cautery of the invention thus enables an almost instantaneous effective cleansing action of the hot wire tip by a simple manipulation which saves a surgeons valuable time and eliminates the aggravation usually associated with the cleaning of heretofore known cauteries. Moreover, a simple temperature control for the tip provides the exact temperature desired, thereby eliminating time-consuming temperature adjustments and minimizing tissue damage. Circuitry is provided which enables the cleaning action due to the highly increased temperature of the tip to be automatic and to decrease automatically after a very short time period.

What is claimed is:

l. Cauterizing apparatus for use with a source of electricity comprising an elongated handle; a wire tip disposed at one end of said handle; a first switch disposed on said handle and electrically connected with said wire tip to control the supply of electricity thereto; a second switch disposed on said handle, said second switch being closed by said handle being placed in a rest position; and electrical circuit means controlled by said second switch and adapted to receive electricity from the source, said circuit means including control means in circuit with said wire tip to control the electricity supplied thereto when said first switch is closed and timing means in circuit with said second switch and said control means and operative to provide an output for a predetermined period of time after said second switch is closed, said timing means providing said output only once after said second switch is closed regardless of how long said second switch remains closed, said control means having a first state supplying electricity from the source to said wire tip at a first voltage to place said wire tip at a cauterizing temperature and a second state supplying electricity from the source to said wire tip at a second voltage greater than said first voltage to place said wire tip at a cleaning temperature greater than said cauterizing temperature and said control means being normally in said first state and being in said second state under the control of said output from said timing means to maintain said wire tip at said cleaning temperature for only said predetermined period of time whereby said wire tip is placed at said cleaning temperature for only said predetermined period of time each time said second switch is closed.

2. The cauterizing apparatus as recited in claim 1 wherein said control means is connected with said timing means such that said control means returns to said first state immediately upon cessation of said output.

3. The cauterizing apparatus as recited in claim 1 wherein said control means includes transformer means having a first output terminal for supplying said first voltage and a second output terminal for supplying said second voltage, a first set of contacts connected between said first output terminal and said wire tip, and a second set of contacts connected between said second output terminal and said wire tip, said first set of contacts being closed when said control means is in said first state and being open when said control means is in said second state and said second set of contacts being open when said control means is in said first state and being closed when said control means is in said second state.

4. The cauterizing apparatus as recited in claim 1 wherein said timing means includes a transistor having a base and an emitter-collector circuit, and a capacitor connected between said base and said second switch; and said control means includes a relay having a winding connected in said emitter-collector circuit and contact means connected with said wire tip, said winding being energized by said transistor when said control means is in said second state.

5. The cauterizing apparatus as recited in claim 4 wherein said electrical circuit means includes a transformer having a secondary winding with first and second end terminals and an intermediate tap, a second capacitor and a first diode connected in series between said first and second end terminals, a first resistor connected with said first end terminal, and a second variable resistor connected with said intermediate tap; said contact means includes a first set of contacts connected between said first resistor and said wire tip and a second set of contacts connected between said wire tip and said second variable resistor; said first and second switches are each connected with said second end terminal; said emitter-collector circuit and said winding are connected across said second capacitor; and said timing means includes a third resistor connected with the junction of said first capacitor and said second switch and a diode connected with said base of said transistor and said third resistor.

6. The cauterizing apparatus as recited in claim 1 wherein said handle has a second end opposite said one end, and said rest position is defined by said handle being positioned with said one end higher than said second end.

7. The cauterizing apparatus as recited in claim 6 wherein said second switch is a gravity operated switch.

8. The cauterizing apparatus as recited in claim 7 wherein said second switch is a mercury switch.

9. Cauterizing apparatus for use with a source of electricity comprising an elongated handle; a wire tip disposed at one end of said handle; a first switch disposed on said handle and electrically connected with said wire tip to control the supply of electricity thereto; a second switch disposed on said handle;

and electrical circuit means controlled by said second switch and adapted to receive electricity from the source, said circuit means including control means in circuit with said wire tip to control the amount of electricity supplied thereto when said first switch is closed and timing means connected with said second switch and said control means and operative to provide an output for a predetermined period of time after said second switch is closed, said control means having a first state supplying electricity from the source to said wire tip at a first voltage to place said wire tip at a cauterizing temperature and a second state supplying electricity from the source to said wire tip at a second voltage greater than said first voltage to place said wire tip at a cleaning temperature greater than said cauterizing temperature and said control means being normally in said first state and being in said second state under the control of said output from said timing means to maintain said wire tip at said cleaning temperature for only said predetermined period of time, said electrical circuit means including transformer means having a secondary winding, and a capacitor and a diode connected in series across said secondary winding, and said timing means including a transistor having a base and an emitter-collector circuit, a capacitor connected between said base and said second switch, and said control means including a relay having a winding connected in said emitter-collector circuit and contact means connected between said secondary winding and said wire tip, said winding being energized by said transistor when said control means is in said second state. 

1. Cauterizing apparatus for use with a source of electricity comprising an elongated handle; a wire tip disposed at one end of said handle; a first switch disposed on said handle and electrically connected with said wire tip to control the supply of electricity thereto; a second switch disposed on said handle, said second switch being closed by said handle being placed in a rest position; and electrical circuit means controlled by said second switch and adapted to receive electricity from the source, said circuit means including control means in circuit with said wire tip to control the electricity supplied thereto when said first switch is closed and timing means in circuit with said second switch and said control means and operative to provide an output for a predetermined period of time after said second switch is closed, said timing means providing said output only once after said second switch is closed regardless of how long said second switch remains closed, said control means having a first state supplying electricity from the source to said wire tip at a first voltage to place said wire tip at a cauterizing temperature and a second state supplying electricity from the source to said wire tip at a second voltage greater than said first voltage to place said wire tip at a cleaning temperature greater than said cauterizing temperature and said control means being normally in said first state and being in said second state under the control of said output from said timing means to maintain said wire tip at said cleaning temperature for only said predetermined period of time whereby said wire tip is placed at said cleaning temperature for only said predetermined period of time each time said second switch is closed.
 2. The cauterizing apparatus as recited in claim 1 wherein said control means is connected with said timing means such that said control means returns to said first state immediately upon cessation of said output.
 3. The cauterizing apparatus as recited in claim 1 wherein said control means includes transformer means having a first output terminal for supplying said first voltage and a second output terminal for supplying said second voltage, a first set of contacts connected between said first output terminal and said wire tip, and a second set of contacts connected between said second output terminal and said wire tip, said first set of contacts being closed when said control means is in said first state and being open when said control means is in said second state and said second set of contacts being open when said control means is in said first state and being closed when said control means is in said second state.
 4. The cauterizing apparatus as recited in claim 1 wherein said timing means includes a transistor having a base and an emitter-collector circuit, and a capacitor connected between said base and said second switch; and said control means includes a relay having a winding connected in said emitter-collector circuit and contact means connected with said wire tip, said winding being energized by said transistor when said control means is in said second state.
 5. The cauterizing apparatus as recited in claim 4 wherein said electrical circuit means includes a transformer having a secondary winding with first and second end terminals and an intermediate tap, a second capacitor and a first diode connected in series between said first and second end terminals, a first resistor connected with said first end terminal, and a second variable resistor connected with said intermediate tap; said contaCt means includes a first set of contacts connected between said first resistor and said wire tip and a second set of contacts connected between said wire tip and said second variable resistor; said first and second switches are each connected with said second end terminal; said emitter-collector circuit and said winding are connected across said second capacitor; and said timing means includes a third resistor connected with the junction of said first capacitor and said second switch and a diode connected with said base of said transistor and said third resistor.
 6. The cauterizing apparatus as recited in claim 1 wherein said handle has a second end opposite said one end, and said rest position is defined by said handle being positioned with said one end higher than said second end.
 7. The cauterizing apparatus as recited in claim 6 wherein said second switch is a gravity operated switch.
 8. The cauterizing apparatus as recited in claim 7 wherein said second switch is a mercury switch.
 9. Cauterizing apparatus for use with a source of electricity comprising an elongated handle; a wire tip disposed at one end of said handle; a first switch disposed on said handle and electrically connected with said wire tip to control the supply of electricity thereto; a second switch disposed on said handle; and electrical circuit means controlled by said second switch and adapted to receive electricity from the source, said circuit means including control means in circuit with said wire tip to control the amount of electricity supplied thereto when said first switch is closed and timing means connected with said second switch and said control means and operative to provide an output for a predetermined period of time after said second switch is closed, said control means having a first state supplying electricity from the source to said wire tip at a first voltage to place said wire tip at a cauterizing temperature and a second state supplying electricity from the source to said wire tip at a second voltage greater than said first voltage to place said wire tip at a cleaning temperature greater than said cauterizing temperature and said control means being normally in said first state and being in said second state under the control of said output from said timing means to maintain said wire tip at said cleaning temperature for only said predetermined period of time, said electrical circuit means including transformer means having a secondary winding, and a capacitor and a diode connected in series across said secondary winding, and said timing means including a transistor having a base and an emitter-collector circuit, a capacitor connected between said base and said second switch, and said control means including a relay having a winding connected in said emitter-collector circuit and contact means connected between said secondary winding and said wire tip, said winding being energized by said transistor when said control means is in said second state. 